function y= rootlocus_AM(x,p)
    rho=x.^(p-1)-x.^(p-2);
    switch p
    case 3
        sigma=5/12.*x.^2+8/12.*x-1/12;
    case 4
       sigma=9/24*x.^3+19/24.*x.^2-5/24.*x+1/24;
    case 5
       sigma=251/720*(x.^4)+646/720*(x.^3)-264/720*(x.^2)+106/720*x-19/720;  
    end
    y=rho./sigma;
end
 